The captain of a Melbourne-bound Qantas flight was almost forced to divert the plane to Sydney on Wednesday, after business class passengers reportedly smelt 'burnt rubber' when a mobile phone became stuck in a seat.

A passenger on board the QF94 flight from Los Angeles said they saw cabin crew run through the plane with fire extinguishers, and described the mid-air drama as "pretty scary", the Herald Sun reported.

Qantas confirmed to ten daily that a business class passenger had dropped their phone which became stuck in the seat.

The phone was then crushed when the passenger attempted to move the seat to retrieve it.

The airline's safety video asks passengers to always seek help from cabin crew in the event of a lost device. Source: Getty Images

Qantas said cabin crew were alerted and managed to contain the situation before the captain communicated with the airline's operation centre and made the decision to continue onto Melbourne.

"Our crew are trained to handle these situations and the crew onboard followed all the correct procedures," a Qantas spokesperson said.

"This incident shows why we ask passengers to seek help from our cabin crew in retrieving their mobile phones."

This isn't the first similar incident on board a Qantas aircraft. In 2016 a passenger on board a Los Angeles to New York flight dropped a personal electronic device under their seat.

When crew members attempted to help retrieve the device the seat moved, crushing the device causing it to start hissing and emitting smoke.

In 2016 crew on board a Qantas aircraft had to use fire extinguishers after a device crushed inside a seat began emitting smoke. Source: Qantas

The Qantas safety video asks passengers to always seek help from cabin crew in the event of a lost device.